Shape-dependence of near-field heat transfer between a spheroidal nanoparticle and a flat surface

TL;DR

This paper investigates how the shape of spheroidal metallic nanoparticles affects near-field radiative heat transfer to a flat surface, revealing significant variations from spherical models.

Contribution

It provides a quantitative analysis of shape dependence in near-field heat transfer, extending understanding beyond spherical particles.

Findings

Heat transfer varies by factors of 1/2 to 2 with particle deformation.

Deviations from dipole models are quantified for spheroidal particles.

Results aid in interpreting near-field thermal microscopy data.

Abstract

We study the radiative heat transfer between a spheroidal metallic nanoparticle and a planar metallic sample for near- and far-field distances. In particular, we investigate the shape dependence of the heat transfer in the near-field regime. In comparison with spherical particles, the heat transfer typically varies by factors between 1/2 and 2 when the particle is deformed such that its volume is kept constant. These estimates help to quantify the deviation of the actual heat transfer recorded by a near-field scanning thermal microscope from the value provided by a dipole model which assumes a perfectly spherical sensor.